The following generally relates to switching devices. More particularly, it is directed towards electromechanical switches such as micro-machined electromechanical relays. However, other types of switches are also contemplated.
A relay generally is a switch that opens and closes under control of an electrical circuit. Traditional relays typically employ an electromagnet that opens or closes one or more sets of contacts. When a current flows through the coil, the resulting magnetic field attracts an armature that is mechanically linked to a moving contact. The movement either makes or breaks a connection with a fixed contact. When the current is switched off, the armature is usually returned to its resting position. The contacts within a relay may be manufactured as normally-open, normally-closed, or change-over (or dual throw) contacts.
Microelectromechanical Systems (MEMS) technology has been leveraged to render micro-machined relays with micrometer size mechanical structures. Such relays can range in size from a micrometer to a millimeter. MEMS based relays have become integral components in technologies involving satellites, aircraft and automobiles and are used in applications such as radar systems for collision avoidance, airborne early warning, tactical radars, and phased array systems.
In many instances, it is difficult to manufacture a micro-machined relay without having one or more actuation electrodes create a capacitive short for high frequency RF signals. In such instances, nearby electrodes drain power, even when they are not touching. Thus, there is a need for improved micro-machined relays that mitigate creation of capacitive shorts with the actuation electrodes.